Lock sling



Jufiy B7, 1951 w. D. BARTLETT LOCK SLING Filed Feb. 4, 1948 INVENTOR.

W D. BARTLETT.

ATTORNEYS Patented July 17, 1951 LOCK SLING William Diestelbrink Bartlett, Cumberland, Md., assignor to Celanese Corporation of America, a

corporation of Delaware Application February 4, 1948, Serial No. 6,220

1 Claim. 1

This invention relates to lock slings, and relates more particularly to a novel lock sling adapted for use in sealing certain elements against undesirable or unauthorized use.

It is often desirable, and sometimes even necessary to prevent serious accidents, to lock certain elements, such as electrical switches, valves, machine parts, etc., to prevent the same from being opened or placed in operation prematurely, or by unauthorized persons.

It is an object of this invention to provide a simple, inexpensive and effective lock sling adapted for use in sealing electrical switches, valves, machine parts, etc. against undesirable or unauthorized use.

Other objects of this invention, together with certain details of construction and combinations of parts, will appear from the following detailed description.

In the accompanying drawing,

Fig. 1 is a perspective view of the novel lock sling of this invention in closed or operative arrangement, and

Fig. 2 is perspective view of the lock sling in open position.

Like numerals indicate like parts throughout both views of the drawing.

Referring to the drawing for a detailed description of the lock sling of this invention, it will be seen that the lock sling consists of two substan tially similar members 3 and 4 each comprising a fiat, relatively narrow bar, which may be of any suitable material, such as iron, steel, brass, etc. One end of each bar is formed into a hook 5, 6 while the major portion of the shank of each bar is provided with an elongated slot 1, 8. To form the lock sling, the two bars 3 and 4 are pivotally mounted, at a point just below the hooked ends, on a pin 9 by which they are held together. In mounting the two bars 3 and 4, they are arranged so that the hooks face each other in a sort of sister-hook arrangement. By this arrange ment, the hooks, when the bars are brought together as shown in Fig. 1, form a substantially circular opening I l which surrounds the element to be sealed.

After locating the hooks 5 and 6 about the equipment, it is desired to seal, the hooks are brought together by the movement of bars toward each other until they overlap and the slots 1 and 8 are in register. The bars 3 and 4 may then be held in closed or operative position by passing a lock through slots 1 and 8. As shown in the drawing, the ends of the hooks 5 and 6 will overlap before any portion of the slots 1 and 8 come into overlapping position so that it is impossible to pass a look through said slots before the hooks have firmly engaged th equipment it is desired to seal. A plurality of locks may be employed, depending upon the number of men working and/or the type of work being carried out on a particular job.

The present invention is applicable where different types of work, such as welding, pipe fitting, rigging, etc., are being done on the same line. The present lock sling can be used to seal the control valve, for example, and th several workers involved on the particular job each will have his own lock on the sling. To open the valve, therefore, the lock sling must be cleared of all looks. Accordingly, the present invention furnishes a foolproof safety device for preventing premature opening of valves controlling steam and flammable and poisonous materials, and of switches controlling flow of electricity and the starting up of machines. It also prevents the placing of chemical systems in operation prematurely, thus avoiding the loss of valuable materials.

It is to be understood that the foregoing detailed description is given merely by way of illustration and that many variations may be made therein without departing from the spirit of my invention.

Having described my invention, what I desire to secure by Letters Patent is:

A look sling comprising a pair of pivotally connected, relatively movable identical bars each having an opening in the shank thereof running substantially the full length of said shank and a hook at the end of each bar, the concave portion of said hooks facing each other and being spaced apart in the open position and overlapping each other in the closed position to form an opening, and the slots being coextensive with each other in the closed position to receive at least one look for the purpose of maintaining the bars in the closed position, said hooks extending toward each other sufficiently so that the ends of the hooks overlap each other before any portion of the slots come into overlapping position.

WILLIAM DIESTELBRINK BARTLETT.

REFERENCES CITED The following references are of record in the file of this patent:

' UNITED STATES PATENTS Number Name Date 1,136,735 Taylor Apr. 20, 1915 1,197,020 Farrar Sept. 5, 1916 1,439,111 Laney Dec. 19, 1922 FOREIGN PATENTS Number Country Date 489,155 Great Britain July 20, 1938 

